GsMYB10 encoding a MYB-CC transcription factor enhances the tolerance to acidic aluminum stress in soybean

MYB transcription factors (TFs) play crucial roles in the response to diverse abiotic and biotic stress factors in plants. In this study, the GsMYB10 gene encoding a MYB-CC transcription factor was cloned from wild soybean BW69 line. However, there is less report on the aluminum (Al)-tolerant gene in this subfamily.

The GsMYB10 gene was up-regulated by acidic aluminum stress and rich in the roots with a constitutive expression pattern in soybean. It was found that GsMYB10 protein contains the MYB and coiled-coil (CC) domains, localizes in the nucleus and holds transcriptional activity. The analysis of the transgenic phenotype revealed that the taproot length and root fresh weights of the GsMYB10-OE plants were greater than those of the wild type when subjected to AlCl₃ treatments. While the accumulation of Al³⁺ in root tip of GsMYB10 transgenic plants (59.37 ± 3.59 µg/g) significantly reduced compared with that of wild type (80.40 ± 3.16 µg/g) which were shallowly stained by hematoxylin under the treatments of AlCl₃. Physiological indexes showed that the proline content significantly increased 39-45% and the malondialdehyde content significantly reduced 37-42% in GsMYB10-OE plants compared with that of wild type. Transcriptomic analysis showed that overexpression of GsMYB10 induced a large number of differentially expressed genes (DEGs) with Al-treatment, which were related to wall modification related genes included PGs (such as Glyma.19g006200, Glyma.05g005800), XTHs (such as Glyma.12g080100, Glyma.12g101800, Glyma.08g093900 and Glyma.13g322500), NRAMPs and ABCs.

In summary, the data presented in this paper indicate that GsMYB10, as a new soybean MYB-CC TF, is a positive regulator and increases the adaptability of soybeans to acidic aluminum stress. The findings will contribute to the understanding of soybean response to acidic aluminum stress.